Ba2–xLaxSnO4+δ layered barium stannate materials: Synthesis, electronic transport, and chemical stability

Abstract

The design and synthesis of new solid oxide materials are important areas in both fundamental and applied chemistry. In the present work, we consider weakly studied Ba2SnO4 layered materials for high-temperature applications. The Ba2–xLaxSnO4+δ (x = 0.05 and 0.1) samples were prepared according to the conventional solid-state synthesis method followed by sintering at 1150–1200 °C. Although a single-phase state was achieved for all the studied compositions, the decomposition of the layered phases into individual oxides (BaO, SnO2/SnO and La2O3) following their long-term storage even under ambient conditions can be explained in terms of their interactions with gas components (H2O and CO2). Nevertheless, the chemical stability of Ba2–xLaxSnO4+δ was slightly improved by La-doping. The electrical characterisation indicated that Ba2SnO4 at 700–900 °C is an n- and p-type conductor with negligible oxygen ionic conductivity. Ba2SnO4 thus represents a relevant research object for fundamental and applied sciences when solving issues with its unsatisfactory chemical stability.